Drivers: hv: Move Hyper-V misc functionality to arch-neutral code

The check for whether hibernation is possible, and the enabling of
Hyper-V panic notification during kexec, are both architecture neutral.
Move the code from under arch/x86 and into drivers/hv/hv_common.c where
it can also be used for ARM64.

No functional change.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1626287687-2045-4-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

arch/x86/hyperv/hv_init.c

@@ -7,10 +7,10 @@
  * Author : K. Y. Srinivasan <kys@microsoft.com>
  */
 
-#include <linux/acpi.h>
 #include <linux/efi.h>
 #include <linux/types.h>
 #include <linux/bitfield.h>
+#include <linux/io.h>
 #include <asm/apic.h>
 #include <asm/desc.h>
 #include <asm/hypervisor.h>
@@ -523,12 +523,6 @@ bool hv_is_hyperv_initialized(void)
 }
 EXPORT_SYMBOL_GPL(hv_is_hyperv_initialized);
 
-bool hv_is_hibernation_supported(void)
-{
-	return !hv_root_partition && acpi_sleep_state_supported(ACPI_STATE_S4);
-}
-EXPORT_SYMBOL_GPL(hv_is_hibernation_supported);
-
 enum hv_isolation_type hv_get_isolation_type(void)
 {
 	if (!(ms_hyperv.priv_high & HV_ISOLATION))

arch/x86/kernel/cpu/mshyperv.c

@@ -17,7 +17,6 @@
 #include <linux/irq.h>
 #include <linux/kexec.h>
 #include <linux/i8253.h>
-#include <linux/panic_notifier.h>
 #include <linux/random.h>
 #include <asm/processor.h>
 #include <asm/hypervisor.h>
@@ -326,16 +325,6 @@ static void __init ms_hyperv_init_platform(void)
 			ms_hyperv.nested_features);
 	}
 
-	/*
-	 * Hyper-V expects to get crash register data or kmsg when
-	 * crash enlightment is available and system crashes. Set
-	 * crash_kexec_post_notifiers to be true to make sure that
-	 * calling crash enlightment interface before running kdump
-	 * kernel.
-	 */
-	if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE)
-		crash_kexec_post_notifiers = true;
-
 #ifdef CONFIG_X86_LOCAL_APIC
 	if (ms_hyperv.features & HV_ACCESS_FREQUENCY_MSRS &&
 	    ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) {

drivers/hv/hv_common.c

@@ -13,9 +13,11 @@
  */
 
 #include <linux/types.h>
+#include <linux/acpi.h>
 #include <linux/export.h>
 #include <linux/bitfield.h>
 #include <linux/cpumask.h>
+#include <linux/panic_notifier.h>
 #include <linux/ptrace.h>
 #include <linux/slab.h>
 #include <asm/hyperv-tlfs.h>
@@ -70,6 +72,16 @@ int __init hv_common_init(void)
 {
 	int i;
 
+	/*
+	 * Hyper-V expects to get crash register data or kmsg when
+	 * crash enlightment is available and system crashes. Set
+	 * crash_kexec_post_notifiers to be true to make sure that
+	 * calling crash enlightment interface before running kdump
+	 * kernel.
+	 */
+	if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE)
+		crash_kexec_post_notifiers = true;
+
 	/*
 	 * Allocate the per-CPU state for the hypercall input arg.
 	 * If this allocation fails, we will not be able to setup
@@ -204,6 +216,12 @@ bool hv_query_ext_cap(u64 cap_query)
 }
 EXPORT_SYMBOL_GPL(hv_query_ext_cap);
 
+bool hv_is_hibernation_supported(void)
+{
+	return !hv_root_partition && acpi_sleep_state_supported(ACPI_STATE_S4);
+}
+EXPORT_SYMBOL_GPL(hv_is_hibernation_supported);
+
 /* These __weak functions provide default "no-op" behavior and
  * may be overridden by architecture specific versions. Architectures
  * for which the default "no-op" behavior is sufficient can leave